SOPAC/CSRC uses the Hatanaka, or compressed RINEX, file compression
strategy for ALL of its RINEX observation files. Hatanaka files
contain a 'd', rather than 'o', as the last filename character.
These files are then unix-compressed, which adds a ".Z" extension.

(Windows users: to unix-uncompress these files, use a utility such as
Winzip).

SOPAC/CSRC provides standard unix-compressed RINEX observation files for the
past 60 days (in addition to Hatanaka-unix compressed files).
These are available from the
SOPAC http archive (password: your e-mail address) or via
ftp.

Downloading the Hatanaka Conversion Program

You can download the crx2rnx Hatanaka to RINEX conversion program from
GSI.
This program must be run on your computer to hatanaka uncompress the file
(after unix-uncompressing it).

Additional Information

The main benefits of moving to this compression strategy for our RINEX
Observation files are a significantly decreased storage requirement
(Hatanaka-unix-compressed RINEX Obs files can take as little as 25
to 30% of the space that a standard unix-compressed file would require),
and a significantly decreased network load (as a result of the storage
improvement). In addition, RINEX Observation file transfers from
SOPAC/CSRC should be markedly faster for our external users. Finally, the
overall reduced storage requirement allows for more data to be on-line.

Program Instructions

(Windows users: open a DOS window and run the program on the command line)

confirm that your "d" file is uncompressed. Some downloads will drop the .Z extension, but the file remains compressed. Try viewing the file using an editor such as notepad. If you can see normal text, the file is uncompressed. If not, rename the file with a .Z extension, and use a file uncompression utility such as winzip (available from winzip.com) to uncompress the file. This is the most common problem with converting "d" files.

confirm that the crx2rnx program and your hatanaka "d" file are in the same directory

execute the following command:

crx2rnx hatanaka_file

where crx2rnx is the operating-system-specific executable (e.g., under Windows: CRX2RNX.EXE);
hatanaka_file is the Hatanaka 'd' file (e.g., bill2070.01d)

A RINEX 'o' file should be created in your working directory.

Note: On Sun and Linux-based operating systems, you will likely have to change the crx2rnx file's permission modes to executable first: chmod +x crx2rnx.